as Andrew covered the technical aspects and pointed out solutions, I
just want to clarify:

In your original mail, you sounded as you were assuming that the
environment variable EPICS_CA_MAX_ARRAY_BYTES was introduced with the
intention of limiting the size of arrays that CA is able to handle.

My statement was: No, it was the other way round. The limitation had
been there from the beginning. The environment variable was introduced
with the intention to overcome this limitation and allow CA to handle
larger arrays.